I've got a requirement that will either end up customizing the Case entity to add alot of custom attributes (not my preferred option as it's only for one business unit), or I could create a specific custom entity to store these business unit specific attributes in, and specifiy the relationship between the Case and Custome Entity (1:1?)
There will be a 1:1 relationship between the case and this custom entity, which doesn't seem to be supported within CRM 4.0, but I should be able to enforce this via a plug-in if required.
Can this be done? If so how.
How this approach work for you? Can you share any issues or suggestions?
In the end we didn't implement this, as the business requirements changed (no shock there!).
Sorry I can't be much more help, but it was some time ago.
I can see the need for the JS. Thanks for the additional information that helps.
When it comes to 1:1 associations, CRM works better by just adding the custom fields to the entity instead of creating a whole new entity (or extension). The effort to enforce the 1:1 constraint and navigation issues may be too costly for the project. I hope this provides some help.
If you look at the database level, all the new fields will be added to the EntityExtensionBase table automatically.